A stall owner who deliberately injects poison into their apples should rightfully be thrown out of the Bazaar. Regardless if the apples are given for free or not.

But the ownership of the apples doesn’t automatically change hands just because their owner decides to poison them.

Forfeiture is the loss of any property without compensation as a result of defaulting on contractual obligations, or as a penalty for illegal conduct.

Where is the court judgement for that?

GitHub is private property, and they have the right to eject anyone from their property for any reason or even no reason at all.

And the code is open-source under the MIT license, so GitHub can do with it as they see fit.

The MIT license doesn’t give you the right to claim ownership over someone else’s code.

You can copy it and claim ownership over that, but it doesn’t allow you to remove the author from their work and then keep the work as your own.

The author has a right to delete it if they want to.

Are you saying that it's a violation of the MIT license to distribute MIT-licensed code if the author asks that you take it down? Because I can assure you, that's not how the MIT license works.

It makes sense if you replace GitHub with Microsoft in your sentence ; )